Nitroso compounds as direct dyes

ABSTRACT

4-nitroso anilines and cosmetically acceptable salts thereof are employed as direct dyes. Compositions for dyeing keratin fibers and containing said 4-nitroso anilines and an alkalizing agent are also disclosed.

This application is a divisional application of application Ser. No.07/554,648 filed July 19, 1990. Now U.S. Pat. No. 5,000,755 as of3/19/91.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to 4-nitroso anilines of the formula I##STR1## wherein R₁ and R₂ are the same or different, and are H, C₁ -C₆alkyl, C₁ -C₆ hydroxyalkyl or polyhydroxyalkyl, C₁ -C₆ alkoxyalkyl orpolyalkoxyalkyl, C₁ -C₆ amino alkyl, C₁ -C₆ dialkylaminoalkyl, or R₁ andR₂ taken together with the nitrogen atom to which they are attached maybe a heterocyclic ring selected from the group consisting of morpholino,pyrrolidino, piperidino and piperazino; R₃, R₄,R₅, and R₆ can be thesame or different, and are H, C₁ -C₆ alkyl, C₁ -C₆ hydroxyalkyl orpolyhydroxyalkyl, hydroxy, C₁ -C₆ alkoxy, C₁ -C₆ hydroxyalkoxy orpolyhydroxyalkoxy, or halogen; and cosmetically acceptable saltsthereof. The instant invention also relates to the use of the compoundsof formula I as direct dyes and to compositions for dyeing keratinfibers containing compounds of formula I.

2. Description of the Prior Art

4-nitroso anilines are known in the art. U.S. Pat. Nos. 4,084,052 and4,023,926 disclose examples of such compounds as reactants in processesfor producing other compounds of interest. In the reactions disclosedthe nitroso group is lost.

U.S. Pat. No. 3,970,423 discloses solutions of4-nitroso-N,N-disubstituted anilines in isopropanol. The disclosed4-nitroso-N,N-disubstituted anilines function as intermediates whichundergo further reaction to produce substituted p-phenylenediamines.

The Colour Index discloses several nitrosophenols as mordant dyes whichform color upon complexation with a metal. The compounds disclosed arenot anilines and merely serve as intermediates to dyes.

British patent 2141437 discloses nitroso compounds for synthesis ofindoaniline and indophenol compounds.

Color Chemistry--Synthesis, Properties and Applications of Organic Dyesand Pigments--Zollinger VCH, 1987, Chapter 6--Nitro and Nitroso Dyes, pp83-84, discloses hydroxy nitroso compounds which are used exclusively asmetal complex dyes.

Although there is a considerable amount of prior art relative to the4-nitroso anilines, we are unaware of any prior art appreciation of theuse of such compounds as direct hair dyes.

SUMMARY OF THE INVENTION

We have found that certain 4-nitroso anilines, as defined below,surprisingly and unexpectedly dye hair bright colors that are shampooand light stable.

The 4-nitroso anilines of the present invention conform to the formula I##STR2## wherein R₁ and R₂ are the same or different, and are H, C₁ -C₆alkyl, C₁ -C₆ hydroxyalkyl or polyhydroxyalkyl, C₁ -C₆ alkoxyalkyl orpolyalkoxyalkyl, C₁ -C₆ amino alkyl, C₁ -C₆ dialkylaminoalkyl, or R₁ andR₂ taken together with the nitrogen atom to which they are attached maybe a heterocyclic ring selected from the group consisting of morpholino,pyrrolidino, piperidino and piperazino; R₃, R₄,R₅, and R₆ can be thesame or different, and are H, C₁ -C₆ alkyl, C₁ -C₆ hydroxyalkyl orpolyhydroxyalkyl, hydroxy, C₁ -C₆ alkoxy, C₁ -C₆ hydroxyalkoxy orpolyhydroxyalkoxy, or halogen; and cosmetically acceptable saltsthereof.

Preferred compounds of formula I include those compounds wherein R₁ andR₂ are the same and are C₁ -C₆ alkyl, C₁ -C₆ hydroxyalkyl or C₁ -C₆alkoxyalkyl.

More preferred compounds of the formula I include those compoundswherein wherein R₁ and R₂ are the same and are C₁ -C₆ alkyl, C₁ -C₆hydroxyalkyl or C₁ -C₆ alkoxyalkyl and R₃, R₄,R₅, and R₆ are,independently, H, C₁ -C₆ alkyl, or hydroxy.

Still more preferred compounds of the formula I are those wherein R₁ andR₂ are the same and are C₁ -C₆ alkyl, C₁ -C₆ hydroxyalkyl or C₁ -C₆alkoxyalkyl; R₃, R₅, and R₆ are hydrogen; and R₄ is H, C₁ -C₆ alkyl, orhydroxy.

Most preferred are compounds of the of the formula I wherein R₁ and R₂are the same and are C₂ -C₄ alkyl, hydroxyethyl or ethoxyethyl; R₃, R₅,and R₆ are hydrogen; and R₄ is hydrogen, methyl or hydroxy.

4-nitrosoanilines of formula I have a number of advantages. They areintensely colored (ξ≈10⁴). They are equal in intensity to4-nitroanilines, a class whose extinction coefficients are among thehighest of the nitro dyes. Moreover, they are more light stable than the4-nitroanilines. This is indeed surprising and unexpected since thenitro compounds fade off-shade upon exposure to light and they are closeanalogues of the nitroso compounds. Thus, prior to our discovery, oneskilled in the art would have expected that 4-nitroso anilines offormula I would exhibit similar light instability.

4-nitroanilines which, as stated above, are close analogies of thenitroso compounds have very low aqueous solubility. Contrary toexpectations the nitroso compounds of formula I are suprisingly verywater soluble. This property allows higher concentrations of the nitrosodyes of formula I in aqueous-based dyeing systems than are attainablewith the nitro dyes.

To illustrate the intensity of the 4-nitroso anilines of formula I, λmaxand logξ were determined in 95% ethanol for representative compounds offormula I. The results are set forth in the following Table I.

It should be noted that, unless indicated to the contrary, percent, asused herein, means by weight based on the total weight of thecomposition.

                  TABLE I                                                         ______________________________________                                        Nitroso aniline of formula I                                                  Compound                      R.sub.3, R.sub.5,                               No.     R.sub.1 & R.sub.2                                                                            R.sub.4                                                                              & R.sub.6                                                                           λmax                                                                         logξ                             ______________________________________                                        1       --CH.sub.2 CH.sub.2 OH                                                                       H      H     428 nm                                                                              4.38                                2       --CH.sub.2 CH.sub.3                                                                          H      H     429 nm                                                                              4.53                                3       --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.3                                                       H      H     416 nm                                                                              4.31                                4       --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3                                                        H      H     430 nm                                                                              4.09                                5       --CH.sub.2 CH.sub.2 OH                                                                       CH.sub.3                                                                             H     430 nm                                                                              4.63                                6       --CH.sub.2 CH.sub.3                                                                          OH     H     401 nm                                                                              4.08                                                              H     335 nm                                                                              4.10                                ______________________________________                                    

EXAMPLE

(A) 0.4% of Compound 1 of Table I (4-nitrosophenyl) diethanolamine wasdissolved in a dye base (containing thickener, preservative,surfactants, solvents, fragrance, alkalizing agent and water). Blendedgrey hair was dyed with the resultant composition for 30 minutes atambient temperature then rinsed and dried. Color quantification andlight fastness were ascertained by the method of Lim and Andersonreported in U.S. Pat. No. 4,799,934, issued Jan. 24, 1989 (see col. 11).Total color change after 10 hours exposure to light in a Fad-o-meter,defined as √(ΔL)² +(Δa)² +(Δb)², was 3.4.

(B) For comparative purposes, 0.4% of (4-nitrophenyl) diethanolamine(the corresponding nitroaniline analogue of the dye employed in part (A)above) was dissolved in the same dye base as was employed in part (A)above. Blended grey hair was dyed with the resultant composition for 30minutes at ambient temperature then rinsed and dried. Colorquantification and light fastness were determined as described in part(A) above. Total color change after 10 hours exposure to light in aFad-o-meter, defined as √(ΔL)² +(Δa)² +(Δb)², was 6.2.

A comparison of light stability results of parts (A) and (B) of thisexample demonstrates the unexpected and surprising substantial increasein light stability of the nitrosoaniline compounds of the presentinvention over their nitroaniline analogues.

(C) Hair dyed in accordance with part (A) of this example and hair dyedin accordance with part (B) of this example were subjected to six handshampoos. Stability of the nitroso-aniline compound 1 of Table I to sixhand shampoos was essentially equivalent to that of its nitroanilineanalogue (4-nitrophenyl diethanolamine) (ΔL for the nitro compound is0.6; ΔL for the nitroso compound is 0.7).

(D) Each of nitrosoaniline Compounds 2, 3, 4, 5 and 6 of Table I whenevaluated as described in part (A) of this example demonstratesunexpected superior light stability as compared to its respectivenitroaniline analogue.

In addition to the use of 4-nitroso anilines of formula I as direct hairdyes, the present invention provides novel hair compositions containinga 4-nitroso aniline of the aforementioned formula I, or a cosmeticallyacceptable salt thereof, in an amount sufficient to function as a directdye on keratin fibers, and a cosmetically acceptable direct dye basecontaining an alkalizing agent in an amount sufficient to facilitatepenetration of the nitroso aniline, or cosmetically acceptable saltthereof, into the keratin fibers to directly dye same.

Preferably, the nitrosoaniline compound of the present invention ispresent in the composition in an amount, of about 0.01% to about 5.0%.

More preferably, such amount is from about 0.05% to about 2.5%.

Most preferably, it is from about 0.1% to about 2%.

The alkalizing agent is preferably selected from the group consisting ofammonia; sodium, potassium, or ammonium carbonate; sodium or potassiumhydroxide; monoalkanolamines, e.g. monoethanolamine, N-methyl,-ethyl,or-propyl ethanolamine, 2-amino-2-methylpropanol, 1-amino-2-propanol,2-amino-1-propanol, N,N-dialkylaminoethanol andN,N-dialkylaminopropanol; alkylamines, trialkyl or trialkanolamines,e.g. triethanolamine; dialkyl and dialkanolamines, e.g. diethanolamine;amino alkyldiols, e.g. 2-amino-2-ethyl-1,3-propanediol; and aminoalkyltriols, e.g. 2-amino-2-hydroxymethyl-1,3-propanediol.

More preferably, the alkalizing agent is selected from the groupconsisting of monoalkanolamines, e.g. monoethanolamine N-methyl,-ethyl,or-propyl ethanolamine, 2-amino-2-methylpropanol, 1-amino-2-propanol,2-amino-1-propanol, N,N-dialkylaminoethanol andN,N-dialkylaminopropanol; trialkyl or trialkanolamines, e.g.triethanolamine; amino alkyldiols, e.g. 2-amino-2-ethyl-1,3-propanediol;and aminoalkyltriols, e.g. 2-amino-2-hydroxymethyl-1,3-propanediol.

Most preferably, the alkalizing agent is selected from the groupconsisting of the monoalkanolamines, e.g. monoethanolamine,N-methyl,-ethyl, or-propyl ethanolamine, 2-amino-2-methylpropanol,1-amino-2-propanol, 2-amino-1-propanol, N,N-dialkylaminoethanol andN,N-dialkylaminopropanol; aminoalkyldiols, e.g.2-amino-2-ethyl-1,3-propanediol; and amino alkyltriols, e.g.2-amino-2-hydroxymethyl-1,3-propanediol.

The alkalizing agent is generally present in an amount of from about0.1% to about 30%.

More preferably, it is present in amount of from about 0.5% to about20%.

Most preferably, it is present in an amount of from about 1% to about10%.

The presence of a thickening agent is desirable. The thickening agentfunctions to increase the viscosity of the composition and reduces (andmost desirably prevents) running of the composition upon application.Suitable thickening agents include sodium alginate; gum arabic; xanthangum; cellulose derivatives, e.g. methylcellulose, hydroxyethylcellulose,hydroxypropylmethylcellulose, carboxymethylcellulose; and acrylic acidderived polymers.

More preferably, the thickening agent is selected from the groupconsisting of gum arabic; xanthan gum and cellulose derivatives, e.g.methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose andcarboxymethylcellulose.

Most preferably, the thickening agent is selected from the groupconsisting of cellulose derivatives, e.g. methylcellulose,hydroxyethylcellulose, hydroxypropylmethylcellulose andcarboxymethylcellulose.

Generally, the thickening agent is present in an amount of from about0.1% to about 10%.

More preferably, it is present in amount of from about 0.5% to about 3%.

Most preferably, it is present in an amount of from about 0.75% to about2.5%.

The compositions of the present invention can include other direct dyesand/or oxidation dyes. Further, the compositions can also includeadjuvants conventionally employed in hair dye compositions, such aswetting agents, emollients, perfumes, antioxidants, sequestrating agentsand the like.

The composition can be packaged under pressure in aerosol containerswith conventional liquified aerosol propellent(s).

The composition is generally applied to keratin fibers, such as humanhair, for a period ranging from about 5 to 45 minutes. The hair is thengenerally rinsed, washed and dried.

What is claimed is:
 1. A composition for direct dyeing of a keratinfiber comprising an amount effective to directly dye such fiber of a4-nitroso aniline of the formula I ##STR3## wherein R₁ and R₂ are thesame or different, and are H, C₁ -C₆ alkyl, C₁ -C₆ hydroxyalkyl orpolyhydroxyalkyl, C₁ -C₆ alkoxyalkyl or polyalkoxyalkyl, C₁ -C₆aminoalkyl, C₁ -C₆ dialkylaminoalkyl,or R₁ and R₂ taken together withthe nitrogen atom to which they are attached may be a heterocyclic ringselected from the group consisting of morpholino, pyrrolidino,piperidino and piperazino; R₃, R₄,R₅, and R₆ can be the same ordifferent, and are H, C₁ -C₆ alkyl, C₁ -C₆ hydroxyalkyl orpolyhydroxyalkyl, hydroxy, C₁ -C₆ alkoxy, C₁ -C₆ hydroxyalkoxy orpolyhydroxyalkoxy, or halogen or a cosmetically acceptable salt thereof;and a cosmetically acceptable direct dye base which contains analkalizing agent in an amount sufficient to facilitate penetration ofthe 4-nitroso aniline of the formula I, or the cosmetically acceptablesalt thereof, into the keratin fiber to directly dye same.
 2. Thecomposition according to claim 1, wherein the alkalizing agent isselected from the group consisting of ammonia, sodium carbonate,potassium carbonate, ammonium carbonate, sodium hydroxide, potassiumhydroxide, monoalkanolamines; alkylamines, trialkylamines,trialkanolamines, dialkylamines, dialkanolamines, amino alkyldiols, andamino alkyltriols; said alkalizing agent being present in an amount offrom about 0.1% to about 30%, based on total weight of the composition.3. The composition according to claim 2, further including a thickeningagent in an amount sufficient to reduce running of the composition whenit is applied to the keratin fiber, said thickening agent being selectedfrom the group consisting of sodium alginate, gum arabic, xanthan gum,cellulose derivatives, and acrylic acid derived polymers; saidthickening agent being present in an amount of from about 0.1% to about10%, based on total weight of the composition.
 4. The compositionaccording to claim 3, wherein the alkalizing agent is present in anamount of from about 0.5% to about 20% and the thickening agent ispresent in an amount of from about 0.5% to about 3%.
 5. The compositionaccording to claim 4, wherein the alkalizing agent is present in anamount of from about 1% to about 10%.
 6. The composition according toclaim 2, wherein the alkalizing agent is selected from the groupconsisting of monoalkanolamines, triakylamines, trialkanolamines,aminoalkyldiols and amino alkyltriols.
 7. The composition according toclaim 2, wherein the alkalizing agent is selected from the groupconsisiting of monoethanolamine, N-methylethanolamine,N-ethylethanolamine, N-propylethanolamine, 2-amino-2-methylpropanol,1-amino-2-propanol, 2-amino-1-propanol, N,N-dialkylaminoethanol,N,N-dialkylaminopropanol, triethanolamine, diethanolamine,2-amino-2-ethyl-1,3-propanediol, and2-amino-2-hydroxymethyl-1,3-propanediol.
 8. The coposition according toclaim 3, wherein the thickening agent is gum arabic, xantham gum,methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose orcarboxymethylcellulose.
 9. The composition according to claim 8, whereinthe thickening agent is methylcellulose, hydroxyethylcellulose,hydroxypropylmethylcellulose or carboxymethylcellulose.